/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina;

/**
 * An <b>Engine</b> is a Container that represents the entire Catalina servlet
 * engine. It is useful in the following types of scenarios:
 * <ul>
 * <li>You wish to use Interceptors that see every single request processed by
 * the entire engine.
 * <li>You wish to run Catalina in with a standalone HTTP connector, but still
 * want support for multiple virtual hosts.
 * </ul>
 * In general, you would not use an Engine when deploying Catalina connected to
 * a web server (such as Apache), because the Connector will have utilized the
 * web server's facilities to determine which Context (or perhaps even which
 * Wrapper) should be utilized to process this request.
 * <p>
 * The child containers attached to an Engine are generally implementations of
 * Host (representing a virtual host) or Context (representing individual an
 * individual servlet context), depending upon the Engine implementation.
 * <p>
 * If used, an Engine is always the top level Container in a Catalina hierarchy.
 * Therefore, the implementation's <code>setParent()</code> method should
 * throw <code>IllegalArgumentException</code>.
 * 
 * @author Craig R. McClanahan
 * @version $Revision: 467222 $ $Date: 2006-10-24 11:17:11 +0800 (星期二, 24 十月
 *          2006) $
 */

public interface Engine extends Container {

	// ------------------------------------------------------------- Properties

	/**
	 * Return the default hostname for this Engine.
	 */
	public String getDefaultHost();

	/**
	 * Set the default hostname for this Engine.
	 * 
	 * @param defaultHost
	 *            The new default host
	 */
	public void setDefaultHost(String defaultHost);

	/**
	 * Retrieve the JvmRouteId for this engine.
	 */
	public String getJvmRoute();

	/**
	 * Set the JvmRouteId for this engine.
	 * 
	 * @param jvmRouteId
	 *            the (new) JVM Route ID. Each Engine within a cluster must have
	 *            a unique JVM Route ID.
	 */
	public void setJvmRoute(String jvmRouteId);

	/**
	 * Return the <code>Service</code> with which we are associated (if any).
	 */
	public Service getService();

	/**
	 * Set the <code>Service</code> with which we are associated (if any).
	 * 
	 * @param service
	 *            The service that owns this Engine
	 */
	public void setService(Service service);

}
